Stitch presser in a weft knitting machine

ABSTRACT

A stitch presser in a weft knitting machine installed on a carriage that slides in a reciprocating fashion on a needle bed and configured such that a presser bar fitted through a presser bar supporting arm joined to a rotation shaft of a motor is advanced into a mouth portion of the weft knitting machine with an electric power supplied to the motor driving the predetermined presser bar in conjunction with the directional switching of the reciprocating motion of the carriage, including a rotation energizing mechanism for rotating the rotating shaft of the motor to a side retracting the presser bar of the weft knitting machine when the electric power is not supplied to the motor for driving the presser bar advanced into the mouth portion.

TECHNICAL FIELD

The present invention relates to a stitch presser in a knitting machine.

BACKGROUND ART

In weft knitting machines with numerous aligned knitting needles on aneedle bed, provided with swinging sinkers in between the knittingneedles, when a knitting needle is raised to knit a new stitch on apreviously knitted stitch hooked by a stitching needle in the course ofknitting performed by the knitting machine, a pressing device such as aswinging sinker or a stitch presser for pressing a stitch or a piece ofknitted fabric is provided so as to prevent the stitch hooked by theknitting needle from being raised along with the raising motion of theknitting needle.

In the swinging sinker, a knitting yarn retaining section is formed andthe knitting yarn of the stitch is retained by the effect of theknitting yarn retaining section. For example, when the knittingoperation is performed, the hooked stitch is thereby able to pass over aposition for clearing a knocking-over.

However, it has been difficult for the knitting yarn retaining sectionof the swinging sinker to retain the stitch in the case of knitting ribstitches using a needle bed in which the knitting needles face eachother in a front to back arrangement, and further, in the case ofknitting a rib-knitted fabric in which the length of a jump-stitchbetween knitting needles is short, or the like.

In addition, it is also considered possible to retain the stitch byproviding a stitch pressing device at a carriage side that wouldfunction as a presser bar applied to a mouth portion of the knittingarea. However, because there is only a slight gap in a mouth portion inwhich part of the swinging sinker is protruding thereto, it is extremelydifficult to provide the presser bar in the mouth portion of the weftknitting machine such that the presser bar performs an advancing andretracting motion, in which a directional switching of the reciprocatingmotion of the carriage is performed at an arbitrary position on theneedle bed.

To solve the above-mentioned problems, the applicant of the presentinvention previously proposed a weft knitting machine, in which theswinging sinker and the presser bar advance and retract to the mouthportion of the needle bed in a relative movement in, for example,Japanese Examined Patent Application Publication No. 6-72347.

That is, the weft knitting machine described in Japanese Examined PatentApplication Publication No. 6-72347, proposed previously, has a sinkerswinging motion control mechanism and a stitch presser control mechanismthat move together and are installed on a carriage, and a stitch barbeing supported by the stitch presser control mechanism is disposedadjacent to an upper end of the carriage such that the presser bar canbe moved by the motion of the stitch presser control mechanism in anadvancing and retracting motion toward the mouth portion disposedadjacent to a top portion of the needle bed. In addition, the sinker isswung by the sinker swinging motion control mechanism that interlockswith the stitch presser control mechanism. Further, the sinker and thepresser bar are controlled to be driven in the advancing and retractingmotion relative to each other when a directional switching of thereciprocating motion of the carriage is performed.

According to the weft knitting machine proposed previously by theinventor of the present invention, the advancing and retracting motionof the presser bar toward the mouth portion performed by the stitchpresser control mechanism in conjunction with the sinker swinging motioncontrol mechanism is performed by directional switching of the rotationof a motor. Therefore, in the course of knitting the fabric, the presserbar of the stitch presser following the advancing direction of thecarriage is advanced into the mouth portion.

Consequently, when a malfunction, such as damage of a knitting cam inthe carriage or the like, occurs in the course of knitting and electricpower supplied to the motor is stopped resulting in a suspension of theoperation of the weft knitting machine, the presser bar remains advancedinto the mouth portion.

When the presser bar of the stitch presser remains advanced into themouth portion, the carriage is moved toward the left side so as to allowthe replacement of the knitting cam in the carriage and is moved acrossa bracket supporting a turning rail. In addition, when the carriage isdismounted from the weft knitting machine, it is possible for thepresser bar to collide with the bracket.

In such a case, there is a problem in that it is troublesome to resumeoperation, because the presser bar is required to be detached bydismantling the same or the carriage is required to be moved whilemanually rotating a motor shaft while continuing to prevent thecollision of the presser bar with the bracket.

The present invention was made in light of the above-described problems.The object of the present invention is that the carriage can be easilymoved when the carriage is required to be moved across the bracket toallow the replacement of the knitting cam in the carriage, or the like,in a state in which the electric power being supplied to the motor hasbeen stopped.

DISCLOSURE OF INVENTION

The present invention provides a stitch presser in a weft knittingmachine to realize the above-described object, in which the stitchpresser in a weft knitting machine is installed on a carriage thatslides in a reciprocating fashion on a needle bed and configured suchthat a presser bar fitted through a presser bar supporting arm joined tothe rotating shaft of a motor is advanced into a mouth portion of theweft knitting machine by electric power supplied to the motor drivingthe predetermined presser bar in conjunction with the directionalswitching of the reciprocating motion of the carriage, and a rotationenergizing mechanism for rotating the rotating shaft of the motor to aside for retracting the presser bar from the mouth portion when theelectric power is not supplied to the motor driving the presser baradvanced into the mouth portion is provided.

Further, in the present invention, the rotation energizing mechanism isformed of a spiral spring or a coil spring, in which an end thereof isjoined to a rotation shaft of the motor or a member joined thereto andthe other end is joined to a fixing member of the carriage side.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation illustrating a weft knitting machine inwhich a stitch presser of the present invention is incorporated;

FIG. 2 is a side view illustrating the weft knitting machine in whichthe stitch presser of the present invention is incorporated;

FIG. 3 is a side view illustrating a section of the stitch presser ofthe present invention;

FIG. 4 is a side view illustrating a retracted state of the stitchpresser of the present invention;

FIG. 5 is a plan view illustrating a section of the stitch presser ofthe present invention;

FIG. 6 is a rear elevation illustrating a section of the stitch presserof the present invention;

FIG. 7 is an exploded perspective view illustrating a section of arotation energizing mechanism of the present invention;

FIG. 8 is a side view illustrating a section of the rotation energizingmechanism of the present invention; and

FIG. 9 is a side view illustrating a state, in which the stitch presserin a section of the rotation energizing mechanism of the presentinvention is retracting.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, with reference to the drawings, the best mode for carryingout the invention is explained.

FIG. 1 is a front elevation illustrating a weft knitting machine inwhich a stitch presser of the present invention is incorporated, FIG. 2is a side view of the same and reference numeral 1 entirely denotes aweft knitting machine.

As illustrated in FIGS. 3 and 4, the weft knitting machine 1 is providedwith a pair of needle beds 3, 3, (one side is not shown) in a front toback arrangement across a center line X of a mouth portion 2 as a lineof symmetry of a upside-down letter V. Further, numerous knittingneedles (not shown) are housed and are able to slide in an advancing andretracting motion in each of the needle beds 3, 3.

Each sinker 5 is disposed between knitting needles and fixed on a pianowire 4 in a longitudinal direction of the needle bed 3 and a pair ofcarriages 6 (shown in FIG. 1) is provided to be moved in reciprocatingmotion capable of being reversed at an arbitrary position by a drivingdevice (not shown).

At the right and left upper ends of each of the carriages 6 in the weftknitting machine 1, as illustrated in FIGS. 5 and 6, a stitch pressercontrol mechanism 9 for operating a presser bar 8 is provided and iscomposed of a rotation energizing mechanism 14 mounted on an outputshaft 11 a of a motor 11 of a driving device 10 and a swinging linkmechanism 15 of the presser bar 8, as illustrated in FIGS. 3 through 7.

As illustrated in FIG. 7, the rotation energizing mechanism 14 isprovided for rotating the output shaft 11 a of the motor 11 to a sidefor retracting the presser bar 8 from the mouth portion 2 of the weftknitting machine 1 when electric power is not supplied to the motor 11,and a casing 18 composed of a housing 16 made of synthetic resin, inwhich space for containing a spring is formed inside thereof, and a thinmetal lid 17 for covering an opening of the housing 16, in which aspiral spring 19 is contained, are provided.

The spiral spring 19 is fixed to a fixing pin 20 formed on an operationarm 23, described later, which is mounted on the output shaft 11 a ofthe motor 11 at an end 19 a at the center of the spiral spring and theother end 19 b at the periphery of the spiral spring is fixed to thehousing 16 (a fixing member of a carriage side) with a fixing member 21.

The above-described swinging mechanism 15 of the presser bar 8 iscomposed of a pair of front and back parallel link plates 24, 24, whichare rotatably supported by fixing members (not shown) at the carriage 6side at their lower ends, a presser bar supporting arm 25 supported bythe upper ends of the parallel link plates 24, 24, an operation rod 26that pushes and pulls a rotatable supporting portion 24 a at an upperend of one of the parallel link plates 24, 24 (at the upper right partin FIG. 3) by means of a rotating force of the operation arm 23 attachedto the output shaft 11 a of the motor 11, and a position detectingmechanism 27, as illustrated in FIGS. 3 through 7.

Further, the shape of the presser bar 8 is approximately the same as theshape of the conventional presser bar 8 having a fabric pressing portion8 a in the weft knitting machine proposed previously by the inventor ofthe present invention, and is attached to an end portion of a side ofthe mouth portion 2 of the presser bar supporting arm 25 by a fixingmember.

A length of one of the parallel link plates 24, 24, which is joined tothe operation rod 26, is larger than that of the other parallel linkplate 24 and the fabric pressing portion 8 a of the presser bar 8thereby performs advancing and retracting swing in the manner of drawingan arc.

The position detecting mechanism 27 is composed of a detecting piece 28attached to an output shaft 11 b of the motor 11 projecting to theopposite side of the motor 11 and two proximity sensors 29, 29 fordetecting the detecting piece 28, as illustrated in FIGS. 5 and 6.

One of the proximity sensors 29, 29 serves as a detector for detectingthe approach of the presser bar 8 into the mouth portion 2 and the otherproximity sensor 29 serves as a detector for detecting the withdrawal ofthe presser bar 8 from the mouth portion 2.

In the thus configured weft knitting machine, the knitted fabric isproduced while the carriage 6 is reciprocatingly sliding on the needlebeds 3, 3. However, when the direction of the reciprocating motion ofthe carriage 6 is switched, the presser bar 8 is changed to the otherpresser bar 8 that follows the direction of the reciprocating motion ofthe carriage 6 when the stitch presser is used for knitting the fabric.Therefore, one of presser bars 8 remains in the mouth portion 2, asillustrated in FIG. 3.

Further, in a state that the presser bar 8 remains in the mouth portion2, the spiral spring 19 is in a state of being wound up by a rotation ofthe output shaft 11 a of the motor 11 resisting an elastic force thereofuntil the proximity sensor 29 of the position detecting mechanism 27 fordetecting the approach of the presser bar 8 detects the detecting piece28 attached to the output shaft 11 b of the motor 11, as illustrated inFIG. 8.

In the state mentioned above, when the electric power supplied to themotor 11 is stopped, the output shaft 11 a of the motor 11 is disengagedand the output shaft 11 a of the motor 11 is reversed by the elasticforce of the spiral spring 19, as illustrated in FIG. 9. As a result,the presser bar 8 is brought to a state of being retracted from themouth portion 2 in FIG. 4 from the state of remaining in the mouthportion 2 in FIG. 3.

Thus, when the presser bar 8 is brought to the state of being outwardlyretracted from the mouth portion 2, the carriage 6 is prevented fromcolliding with a supporting bracket 31 for supporting a turning rail 30,shown in FIGS. 1 and 2, even when the carriage 6 has been detached fromthe needle bed 3.

In addition, although the spiral spring is used in the embodimentdescribed above, the shape of the spring is not limited to a spiral anda coil spring having a circular cross section can of course be used.

As explained above, the stitch presser in the weft knitting machine ofthe present invention is provided with the rotation energizing mechanismfor rotating the rotation shaft of the motor to a side for retractingthe presser bar from the mouth portion of the weft knitting machine whenthe electric power supplied to the motor is stopped. Therefore, when,for example, a malfunction occurs in the weft knitting machine and theelectric power to be supplied to the weft knitting machine is stopped,the drive of the motor that was driving the presser bar to advance intothe mouth portion is stopped. Then, the rotation shaft of the motor isdisengaged so that it rotates freely, and is rotated in such a directionthat the presser bar can be retracted from the mouth portion by therotation energizing mechanism.

Consequently, because the presser bar is retracted from the mouthportion, the carriage can be moved across the bracket withoutrestriction so as to be detached from the weft knitting machine for anunexpected replacement of the knitting cam, or the like. Therefore, itis advantageous that the trouble and time required for moving thecarriage to be detached from the weft knitting machine can be reduced.

1. A stitch presser in a weft knitting machine installed on a carriage that slides in a reciprocating fashion on a needle bed and configured such that a presser bar is advanced into a mouth portion of the weft knitting machine in response to rotation of a rotating shaft of a motor with electric power supplied to the motor driving the predetermined presser bar in conjunction with a directional switching of the reciprocating motion of the carriage, comprising: a rotation energizing mechanism for rotating the rotation shaft of the motor to a side for retracting the presser bar from the mouth portion of the weft knitting machine when the electric power is not supplied to the motor for driving the presser bar advanced into the mouth portion.
 2. The stitch presser in a weft knitting machine according to claim 1, wherein the rotation energizing mechanism is formed of a spiral spring or a coil spring, and wherein an end thereof is joined to the rotation shaft of the motor or a member moving in response to rotation of the motor, and the other end thereof is joined to a fixing member of the carriage side. 